Just about all the bad stuff is gone. Most everything we see is physiologic. (The hotspot in left upper abdomen is in the stomach, and the CT didn’t show anything, but we’ll still watch it.)
This isn’t a particularly unusual scenario following therapy. So I complimented my friend on another successful administration of his potions and poisons. At this point, he shifted uncomfortably from foot to foot. He finally looked up and said, “But we only treated the lower spine lesion with radiotherapy. We didn’t treat the other areas!” We called in the treating Rad Onc, who was equally surprised. “Wow. This would have to be an abscopal effect. I’ve never seen one before. There might be 20 or so reports out there…”
What in the world is the “Abscopal Effect”?
From the Wikipedia:
The abscopal effect is a phenomenon in the treatment of metastatic cancer where localized treatment of a tumor causes not only a shrinking of the treated tumor, but also a shrinking of tumors outside the scope of the localized treatment. R.H. Mole proposed the term “abscopal” (‘ab’ – away from, ‘scopus’ – target) in 1953 to refer to effects of ionizing radiation “at a distance from the irradiated volume but within the same organism.”
Initially associated with single-tumor, localized radiation therapy, the term “abscopal effect” has also come to encompass other types of localized treatments such as electroporation and intra-tumoral injection of therapeutics. However, the term should only be used when truly local treatments result in systemic effects. For instance, chemotherapeutics commonly circulate through the blood stream and therefore exclude the possibility of any abscopal response.
The mediators of the abscopal effect of radiotherapy were unknown for decades. In 2004, it was postulated for the first time that the immune system might be responsible for these “off-target” anti-tumor effects. Various studies in animal models of melanoma, mammary, and colorectal tumors have substantiated this hypothesis. Furthermore, immune-mediated abscopal effects were also described in patients with metastatic cancer. Whereas these reports were extremely rare throughout the 20th century, the clinical use of immune checkpoint blocking antibodies such as ipilimumab or pembrolizumab has greatly increased the number of abscopally responding patients in selected groups of patients such as those with metastatic melanoma.
Visually (also from the Wiki):
“Proposed mechanism of the abscopal effect, mediated by the immune system. Here, local radiation causes tumor cell death, which is followed by adaptive immune system recognition, not unlike a vaccine.’
So, this rare phenomenon probably has a scientific explanation. I’m used to seeing cancer and other disease cured or at least kept at bay, including things we were taught not that long ago were “incurable”. I see what was once impossible happen pretty much every day. And that’s amazing enough when you think about it.
via Blogger https://ift.tt/2we9gGX August 18, 2018 at 08:39PM